Production of anthraquinone azines



Patented Jan. 24, 1933 UNITED STATES PATENT OFFICE PAUL NAWIASKY ANDLUDWIG EIFFLAENDER, OF LUDWIG-SHAFEN-ON TI-IE-RHINE,

GERMANY, ASSIGNORS TO GENERAL ANILINE WORKS, 1110., OF NEW YORK, N; Y

CORPORATION OF DELAWARE PRODUCTION OF ANTHRAQ'O'INONE AZINES No Drawing.Application filed December 11, 1930, Serial No. 501,745, and in GermanyOctober 8, 1926.

The present invention relates to improvements in the production ofN-dihydro- 1.2.1.2-anthraquinoneazines.

This application is a continuation-in-part of my copending applicationSer. No. 229,258 for improvements in the production of N-dihydro-1.2.1.2j-anthraquinoneazines, filed October 27, 1927. V i

It is known that the valuable blue dyestufiN-dihydro-1.2.1.2-anthraquinoneazine can be obtained by the action offused caustic alkali on 2-aminoanthraquinone, with or without theaddition of oxidizing agents, the melt being poured into water andoxidized with air. In order to improve the yield, it has also beenproposed to add to the melt, salts of low fatty acids, such for exampleas.

potassium formate, potassium acetate, and the like, in the presence, ifrequired, of an inert diluent, or to add alcoholates or phenolates, suchas sodium butylate, sodium phenolate, and the like. i

We have now found that still better yields of the said dyestufi' or ofits derivatives when starting from substituted 2-amino-anthraquinone,may be obtained if salts of low fatty acids, namel of formic, acetic orpropionic acid, are ad ed to the caustic alkali melt in conjunction withsalts of fatty acids containing at least 4 carbon atoms. Salts of thelatter kind comprise, for example, alkali metal salts of butyric acid(normal or iso-), valeric acid, stearic and palmitic acid.

According to the present invention the caustic alkali melt may becarried out with an addition of oxidizing agents or also in the absenceof such agents, and preferably with fused caustic potash-soda.

The following examples will further illustrate the nature of the saidinvention, but the invention is not limited thereto. parts are byweight.

' Example 1 15 parts of dehydrated sodium acetate are stirred into 200parts of a mixture, in molecular porportions, of caustic potash and sodaat a temperature of about 200 Cl, 20 parts of soap being then added.Thereupon 75 parts of ,B-aminoanthraquinone are introduced, and themixture is stirred at a tem- The I our hands.

perature of from 200 to 210 C. until the production of the dyestuffceases'to increase.

The separation of the dyestuif is effected in the usual manner.

i Ewample 2 parts of dehydrated sodium acetate are. introduced into amelt of 2,000 parts of caustic potash-soda at a temperature of 250 G, 45parts of potassium isobutyrate being then added and the mixture stirreduntil uniform distribution has taken place. The mixture is then cooleddown to a temperature of 210 C. and 500 parts of ,B-aminoanthraquinoneare introduced in such a way that the temperature does not rise above230 C. The whole mixture is maintained at a temperature of 225 C. untilthe production of dyestuif ceases to increase and ,B-aminoanthraquino'necan no longer be detected. The melt is then 70 treated in the usual way.

The potassium isobutyrate may be replaced by potassium butyrate whichgives an equally good result.

What we claim is 1. The process of producing N-dihydro-1.2.2.1-anthraquinoneazines, which comprises subjecting a2-aminoanthraquinone to the action of a caustic alkali melt in thepresence of a salt of a low fatty acid in conjunction with asalt of afatty acid containing at 7 least- 5 carbon atoms. I

2. The process of producing N-dihydro- 1.22.1-anthraquinoneazines, whichcomprises subjecting a 2-aminoanthraquinone to the action of a causticpotash-soda melt in the presence of a salt of a low fatty acid inconjunction with a salt of a fatty acid containing at least 5 carbonatoms.

3. The process of producing N-dihydro- 1.22.1 anthraquinoneazine, whichcomprises subjecting a 2-aminoanthraquinone to the action of a causticalkali melt in the presence of a salt of a low fatty acid in conjunctionwith an alkali metal salt of a valeric acid.

In testimony whereof we have hereunto set PAUL NAWIASKY.

